Method for producing concentrated food products with fractionation concentration

ABSTRACT

An improved processing method and system for producing tomato paste and other food products affected by viscosity. Tomatoes are processed into tomato juice. The juice is provided to a decanter that separates or fractionates the juice into two portions—a thicker, more viscous cake portion and a thinner, less viscous serum portion. The serum portion is concentrated by removing a portion of water using an evaporator such as a thin film or juice evaporator. The cake portion can be concentrated if necessary with a drier. The serum and cake portions are recombined to produce a tomato paste having improved color, texture, flavor and nutrition.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.10/489,984, filed Mar. 17, 2004, now U.S. Pat. No. 7,074,451 priority ofwhich is claimed under 35 U.S.C. §120, which is a national stageapplication of International Application No. PCT/US02/29606, filed Sep.19, 2002, which claims priority under 35 U.S.C. §119 of U.S. ProvisionalApplication No. 60/323,771, filed Sep. 19, 2001, all of which areincorporated herein by reference as though set forth in full.

FIELD OF THE INVENTION

This invention relates to food products and a system and method forproducing food products. In particular, the present invention relates totomato paste and similar food items that are produced by separatingtomatoes or food items into portions or fractions having differentviscosity, concentrating one or more of the portions, and re-combiningthe portions to form a food product such as tomato paste.

DESCRIPTION OF RELATED ART

Tomatoes or derivative tomato products such as juice, puree and pastecan be added as food ingredients to a food product to provide, forexample, flavor, color, texture and viscosity. Tomato paste is onecommon product produced from tomatoes. To produce tomato paste, water istypically removed from tomatoes or tomato juice via dehydration orevaporation.

Using tomato paste can be advantageous, compared to fresh tomatoes ortomato juice, for a number of reasons. For example tomato paste mayprovide improved taste, appearance, and be advantageous for thefollowing economic considerations:

a. Storage capabilities—aseptically bulk packaged tomato paste can bestored for extended periods of time (e.g., up to several years) prior toconsumption. These storage capabilities provide flexibility in shipping,transportation, and sales.

b. Reduced shipping costs—bulk tomato paste typically weighs less thanraw tomatoes as a result of lower water content. Thus, shipping costsare reduced.

c. Supply flexibility—a year round supply of tomato paste can bemaintained in spite of the season for harvesting fresh tomatoes beingapproximately 100 days.

d. Cooking requirements—some products require tomato paste rather thanfresh tomatoes or tomato juice based on a recipe's water contentlimitations.

Known system typically process tomatoes by directly processing theentire or unfractionated tomato stream. For example, tomatoes arechopped into a liquid or liquid-like product and supplied to anevaporator. The unfractionated tomato stream becomes increasinglyconcentrated as the evaporator heats the tomato stream and removes waterfrom the stream.

Such conventional systems, however, typically have a number ofshortcomings. First, as the paste product becomes more viscous (thickeror more resistant to flow), the tomato paste becomes increasingly moredifficult to manipulate. The increasing viscosity is the result ofvacuum, heat, shear and recirculation of the thickening paste. Portionsof the paste can be “burned” onto evaporator surfaces as the surfacesare heated and the viscous paste can stick to the surfaces.Consequently, the resulting tomato paste can be burned or overheated,resulting in diminished tomato paste quality, e.g., reduced color,flavor and nutrients.

Moreover, additional cleaning and maintenance of evaporator equipmentmay be necessary as a result of the “burning” effect. Maintenance andcleaning requires additional time and resources which, in turn, lead toinefficient processing and reduced production capabilities.

Additionally, in order to process the increasingly viscous paste, knownsystems typically use more powerful evaporators that can handle higherviscosity paste. These types of evaporators may use re-circulationturbine pumps to pump and re-circulate the increasingly viscous tomatopaste. These more powerful, larger evaporators usually are moreexpensive. Further, larger evaporators typically consume more power andare more expensive to operate. Additionally, processing unfractionatedstreams of tomato juice typically takes a significant amount of time(e.g., two to three hours for a reasonable sized batch). Consequently,systems that produce tomato paste by directly processing unfractionatedstreams of juice often are not time, cost, and energy efficient and canproduce lower quality tomato paste.

Other known systems separate portions of tomato paste to form derivativeproducts. For example, a portion can be removed from a tomato juicestream, and the evaporator can concentrate the remaining portion.Typically, however, these known systems also have a number ofshortcomings. First, these systems produce separated components that areuseful only in limited circumstances based on the quality and nature ofthe components. For example, the thicker component is typically a dense,powder-like substance that can be milled and used as a flavoring. Thethicker component, however, is often not suitable for tomato paste.Further, the remaining portion is often too thin to be used as tomatopaste. Thus, these known systems separate components of a tomato stream,but may not be able to produce tomato paste in an effective matter.Further, the dense powder and liquid components typically cannot becombined due to their different compositions. If the portions arecombined, a low quality, chalky tomato paste-like product may beproduced having diminished color, texture, and taste. Thus, knownsystems that separate tomato components are often not as effective asdesired to produce quality tomato paste in an efficient manner.

There is a need, therefore, for a system and a method for producingtomato paste and other similar products with improved viscosity, color,nutrients and flavor in a more cost, energy and time efficient manner.

SUMMARY OF THE INVENTION

The present invention provides-an improved system and method forprocessing tomato products to produce a paste with enhanced taste andcolor in a more efficient manner.

One embodiment of the present invention provides a system and methodthat processes tomatoes into a stream of tomato “juice.” The juicestream is separated—or fractionated into two portions—a serum portionand a cake portion. The serum portion has a lower viscosity than thecake portion. In other words, the cake portion is thicker and moreresistant to flow relative to the serum portion. After these portionsare separated, the serum portion is concentrated using, for example, anevaporator. The cake portion can also be concentrated, if desired, usinga drier mechanism or other suitable evaporator. The cake portion and theconcentrated serum portion are re-combined to form an improved tomatopaste. Alternatively, the portions can be separately processed and/orpackaged as separate products or ingredients.

The cake portion includes a majority of insoluble solids relative to theserum portion. As a result, the serum portion can be concentrated moreeasily with an evaporator for enhanced appearance and taste. Further,less evaporation time and energy are required to process the serumportion, thereby reducing capital and energy costs associated with theevaporator. Thus, less expensive and robust evaporators can be used. Adrying mechanism can be used to concentrate the cake instead of anevaporator. As a result, the present invention can reduce or eliminatedegradation of tomato juice stream resulting from “burn on” of cakecomponents onto evaporator surfaces. Further, cleaning and maintenancecosts can be reduced while producing a tomato paste product withenhanced flavor, texture, color and nutrition.

Also in accordance with the present invention, a decanter can be used toseparate tomato juice into cake and serum portions. The decanter canseparate the portions using different techniques. One exemplary decanteris configured as a centrifuge with an inner weir. As the centrifugerotates, the cake gravitates to the inner surface of the decanter and isseparated from the serum with the weir. The fractionated cake portioncan advantageously have the following characteristics: about 5%-35% ofthe tomato stream by weight, about 5%-60% insoluble solids by weight,about 3%-16% soluble solids by weight and a concentration of about 3-13brix. The fractionated serum portion can have the followingcharacteristics: about 65%-95% of the tomato stream by weight, about 0(trace)-10% insoluble solids by weight, about 3%-17% of soluble solidsby weight and a concentration of about 3-16 brix.

In further accordance with the invention, if the cake and serum streamsare re-combined, the concentration of the re-combined stream can have aconcentration of about 15-40 brix. If the cake and serum portions arenot re-combined, the cake portion can have a concentration of about5-99% of solids. For example, a thick cake can be formed if the cakeportion is about 5% solids, whereas a powder that can be milled can beformed if the cake portion is about 99% solids. The serum portion can beconcentrated to a concentration of about 22-75 brix.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 is a general block system diagram of portions used to process astream of tomato juice by fractionating the juice into cake and serumportions, and re-combining the portions to form a tomato paste;

FIG. 2 is a general block system diagram of portions used to processtomato juice by fractionating the juice into cake and serum portions,and separately processing the portions;

FIG. 3 is a system diagram illustrating one example system configurationand example operating parameters;

FIG. 4 is a diagram illustrating an example decanter configuration forfractionating a tomato juice stream into cake and serum portions;

FIGS. 5A-B are flow diagrams illustrating a method of producing tomatopaste by separating the tomato juice stream into cake and serumportions, and re-combining the portions to form tomato paste; and

FIGS. 6A-B are flow diagrams illustrating a method of separating thetomato juice stream into cake and serum portions, and separatelyprocessing the portions.

DETAILED DESCRIPTION

In the following description of embodiments of the invention, referenceis made to the accompanying drawings which form a part hereof, and whichis shown by way of illustration specific embodiments in which theinvention may be practiced. It is to be understood that otherembodiments can be utilized as structural changes maybe made withoutdeparting from the scope of the present invention.

One aspect of the invention provides a processing system thatfractionates or separates tomato juice or a tomato stream or othersimilar substance into different portions, i.e., cake and serumportions, and later re-combines the portions. As generally illustratedin FIG. 1, the processing system transports a product 100, such astomatoes, on a conveyor or other transport system 105. Those persons ofordinary skill in the art will recognize that various tomato products100 can be processed, such as fresh tomatoes, tomato juice, tomatoslurry, a mixture of tomato juice and tomato pulp, or other tomatoderivatives. However, the invention is not so limited. Those persons ofordinary skill in the art will also recognize that other food productscan be processed. For example, the present invention can be used toprocess or produce other food items that are affected by viscosity suchas, for example, chili paste (which can be thicker than tomato paste),and other Suit or vegetables where limiting viscosities prevent orinhibit evaporation, such as peas for pea soup. A further exampleapplication of the present invention is to process apples or apple ciderto form a concentrated apple puree. The puree can be used to make applepies and other apple products. However, for purposes of explanation,this specification refers to processing raw tomatoes into a “juice” thatis fractionated into serum and cake portions that can be re-combined toform a tomato paste after one or more of the portions has beenconcentrated.

Tomatoes are transported along the conveyor and are chopped with achopping mechanism 110. Chopped tomatoes are provided via a pump 115 toan enzyme processor 120 for enzyme breaking or inactivation. Thechopping mechanism 110 can be one of many mechanisms that chops tomatoesinto tomato pieces including, but not limited to, a knife, a rotatingknife, rotating blades, a blender mechanism, and other cutting andchopping devices capable of cutting fruits and vegetables.Alternatively, the chopper 110 and pump 115 can be combined into asingle unit. For example, a device that combines both chopping andpumping functions is chopper pump model no. STH4R12S, available fromVaughn, Co., Inc., Montesano, Wash.

The enzyme processor 120 removes selected enzymes that affect theviscosity of chopped tomatoes. In other words, enzymes are inactivatedduring “hot breaking” or “enzyme breaking.” Example enzymes that can beremoved or inactivated include pectin galacturonase, pectin methylesterase and other enzymes in fresh tomatoes. One exemplary enzymeprocessing or “breaking device” 120 that can be used is model G ElDorado, available from Rossi & Catelli S. P. A., Parma, Italy. Thisexemplary enzyme breaking device can be set to operate at differentconfigurations and temperatures for hot or cold breaking, as laterdescribed.

If necessary, the chopped tomatoes can be processed with an initial orpreliminary evaporator 125. The initial evaporator 125 removes a portionof the water from the chopped tomatoes to make the tomatoes more viscousor thicker. One exemplary evaporator 125 that can be used for thispurpose is a T.A.S.T.E. evaporator, available from FMC Food Tech, Inc.,Citrus Systems Division, Lakeland, Fla. Another exemplary evaporator 125that can be used is an EC series rising film evaporator, available fromTetra-Pak, Inc., Vernon Hills, Ill.

Enzyme inactivated tomato pieces can be further processed and filteredusing a pulper or finisher 130. One exemplary pulper/finisher 130 thatcan be used is a Butterfly TC6 depulper, available from Rossi & CateriS. P. A., Parma, Italy. The pulper or finisher 130 removes solids fromthe tomatoes such as outer skins and/or seeds to form a tomato “juice”or “juice stream” 132. More specifically, one type of thepulper/finisher 130 forces chopped tomatoes through a screen, filter, orfilter screen having holes or apertures of specific size. Example screensizes that can be used to remove seeds and/or peels to form the juicehave apertures with dimensions of approximately 0.027″ to 0.156″. Mosttomato seeds can be removed with screen having apertures of up to0.074″. As tomato pieces pass through the apertures, seeds and/or peelsare removed or filtered from the tomatoes to produce tomato juice 132.As a result, the juice 132 includes portions less than or equal to thesize of the finisher-pulper 130 screen. Different food products can beprocessed with different pulper-finisher apertures depending on thequantity and size of seeds and desired smoothness or coarseness offibers in the juice 132.

Those persons of ordinary skill in the art, however, will recognize thatone or more of the portions 110-130 may not be necessary depending onthe characteristics and type of tomato or food product processed.However, for purposes of explanation, this specification refers to thepulper/finisher 130 producing “tomato juice” 132, although juice 132 maybe formed at different stages.

The tomato juice 132 is supplied to a decanting centrifuge 135(hereafter referred to as decanter 135). The decanter 135 separates orfractionates juice 132 into a serum portion 140 and a cake portion 145.One exemplary decanter that can be utilized is a Tetra Aldex® decanter,model no. NX438, available from Tetra-Pak, Inc., Vernon Hills, Ill. Thisexample decanter uses a weir to separate the portions, as will be laterdescribed in further detail in connection with FIGS. 3 and 4. Anotherdecanter that can separate tomato juice or tomato puree 132 into cake140 and serum 145 portions is a clarifier decanter, model no. CA755-0012 or model no. CA 755-01-12, available from Westfalia Separator,Inc., Northvale, N.J.

Those persons of ordinary skill in the art will recognize that variousdecanters and decanter configurations can be used. For example, insteadof a centrifuge, the same fractionation technique can be achieved byusing a press with one or more apertured filter screens (which can beused for processing apples or apple cider). A further alternativefractionation device can be a filtration membrane such as anultrafiltration membrane. However, for purposes of explanation, thisspecification refers to a decanting centrifuge for fractionating a juicestream 132 into serum 140 and cake 145 portions.

The serum portion 140 is concentrated using an evaporator 150. Theoutput of the evaporator 130 is a concentrated serum 160. Evaporator 150can be the same as the initial evaporator 125 or similar. However, sincethe serum is thinner and less viscous than the cake portion or anunfractionated tomato stream, a smaller (and usually less expensive andmore energy efficient) evaporator 125 can advantageously be used toconcentrate the serum portion 140. One exemplary evaporator 125 that canconcentrate the serum portion 140 is a juice evaporator, ThermallyAccelerated Short Time Evaporator (T.A.S.T.E.) 6 effect 6 stageavailable from FMCFoodTech Food Processing Systems, Parma, Italy. As aresult of using a smaller evaporator, capital expenditures and energycosts for processing food products can be reduced. Further,concentration times can also be reduced since the serum is thinner thanan unfractionated stream and easier to process in a shorter period oftime. For example, some known systems may take an hour or more toprocess a batch of unfractionated tomatoes into a tomato paste. However,the thinner, fractionated serum can be processed in less time with asmaller evaporator (e.g., 5 minutes-1 hour).

The cake portion 145 can also be concentrated, if necessary with, e.g.,a drier 155 to produce a dried cake portion 165. One exemplary drier 155that can be used is a Refractance Window™ drier, available from MCDTechnologies, Inc., Tacoma, Wash. With this exemplary drier, the cake145 can be sprayed across the belt with a sprayer (not shown) and passedthrough the drier to evaporate water from the cake, thereby forming aconcentrated cake portion 165. Other evaporation systems can also beused to concentrate the cake.

The concentrated serum portion 160 and the cake portion 145 (orconcentrated cake 165, if desired) are re-combined using a combiner orcombination unit 170 to form a re-combined stream 171 or tomato pasteproduct. One exemplary combination unit 170 that can be used is apositive displacement pump, model no. 220, available from WaukeshaCherry Burrell Products, Delvan, Wis. Alternatively, the combiner 170can be an in-line static mixer, e.g., model no. SAN 42499, availablefrom Komax Systems, Inc., Wilmington, Calif. Indeed, various combiners170 can be used. The re-combined or second juice stream 171 output bythe combiner 170 is sterilized with a sterilization unit 180, asnecessary, and cooled with a cooling mechanism or cooler 185, asnecessary. The tomato paste can be packaged, shipped, stored for laterconsumption, or farther processed as desired.

Referring now to FIG. 2, in an alternative embodiment, the serum 140 andcake 145 portions are not re-combined. Instead, the serum and cakeportions are processed individually. More specifically, the juice stream132 is processed by the decanter 135 to produce the serum 140 and cake145 portions as previously described. The serum portion 140 isconcentrated with an evaporator 150 to produce a concentrated serumportion 160. The cake portion 145 can be concentrated, if necessary,with a drier to produce a concentrated cake portion 165. However, thecake and serum portions are then separately processed, e.g., aresterilized with one or more sterilizers 180, cooled with one or morecoolers 185 and packaged with one or more packagers 190. Thus, in thisalternative embodiment, serum and cake portions are separately producedwhereas tomato paste is ultimately produced by re-combining the portionsas illustrated in FIG. 1. The resulting concentrated serum 160 can beused as a soup base or flavoring since it is thinner than the cake. Thecake portion 145 or concentrated cake portion 165 can be used as a coloringredient, a source of nutritional fiber for foods including a tomatoproduct, and a source of lycopene.

These and other aspects of the present invention are described infurther detail with reference to the system and decanter diagram of FIG.4, and flow diagrams of FIGS. 5A-B and 6A-B.

FIG. 3 illustrates one exemplary system configuration for processingtomatoes by re-combining the serum and cake portions to form the tomatopaste. Of course, those persons of ordinary skill in the art willrecognize that the following system parameters are merely illustrativeof many system parameters and are not so limited. Further, FIG. 3illustrates the primary portions of the system. For example, dependingon the state and type of tomatoes, chopping, pulping, and enzymebreaking may be performed. Additionally, one or more additional pumpsmay be used to direct the juice, serum portion, cake portion, and tomatopaste product to the next processing portion.

Initially, tomatoes 100, are provided to an evaporator 125, such as athin film evaporator, at a rate of about 112.4 tons per hour (tons/hr)at a concentration of about 5 brix. Different tomatoes with differentbrix concentrations can be processed, but the concentration of rawtomatoes can range from 3-7 brix. The concentration measurement “brix”refers to a percentage of sugar and other soluble solids present in thetomatoes. Thus, for example, tomato pieces having 3-7% sugar or solublesolids have a concentration of 3-7 brix. Tomato products having higherbrix concentrations are generally sweeter and more flavorful as a resultof higher sugar content.

The evaporator removes moisture from the tomatoes at a rate of about50.0 tons/hr and outputs the tomatoes at about 62.4 tons/hr with aconcentration of about 9 brix. The tomatoes can be processed by a pulper130 resulting in a juice stream 132. The juice stream 132 is thenprocessed by the decanter 135 at about 242 gallons per minute(gal/minute). The decanter fractionates the juice into serum and cakeportions 140, 145 that are pumped through respective pumps 300, 305. Theserum is pumped to an evaporator 150, such as a thin film/juiceevaporator, at a rate of about 53.1 tons/hr at a concentration of about9.0 brix. The cake 145 is pumped to a drier 155 at a rate of about 9.4tons/hr at a concentration of about 9.0 brix. As previously mentioned,evaporator 150 can be a less robust (and less expensive) evaporator,such as a thin film juice evaporator, since it is processing the “thin”serum portion 140 of the juice stream 132. The evaporator 150 removesmoisture from the serum 140 at rates of about 13.8 tons/hr and 25.6tons/hr, thereby concentrating the serum. The concentrated serum 160exits the evaporator 150 at a rate of about 13.6 tons/hr at an increasedconcentration of about 35.0 brix. If needed, the concentrated serum 160can be further concentrated with additional evaporators 310 and 315.However, this example configuration does not utilize these additionalevaporators as shown by consistent flow rates into the combiner 170, butare illustrated to show additional optional concentrating.

The drier 155 removes moisture from the cake 145 at a rate of about 1.8tons/hr, resulting in concentrated cake 165 exiting the drier 155 at arate of about 7.6 tons/hr with a concentration of about 11.2 brix. Thosepersons of ordinary skill in the art will recognize that the drier 155is optional. The concentrated serum 160 and the cake 145 or concentratedcake 165 are re-combined using combiner 170, such as a static mixer. There-combined stream 171 includes about 64% serum by weight and about 36%cake by weight. The resulting stream 171 or tomato paste product exitsthe combiner 170 at a rate of 23.0 tons/hour with a concentration of26.5 brix. Those persons of ordinary skill in the art will recognizethat many variations on the previously described operating parameterscan be used.

Turning to FIG. 4, one exemplary decanter 135 includes a centrifuge body400 supported by base 405. The centrifuge body 400 rotates around abearing 410. The decanter includes an input 420, weir 430, serum output440, cake output 450 and a scraping mechanism such as rotating auger460.

Juice 132 is provided to the decanter 135 through the input 420. As thedecanter rotates, the thicker cake portion is separated from the serumsection. The cake portion gravitates to the inner surfaces 402 of thecentrifuge body 400. The less dense serum portions remain in the generalmiddle area of the decanter, i.e., the thinner serum does not tend tomigrate to the inner surfaces of the centrifuge body. The cake portions145 collecting around the inner surfaces 402 of the centrifuge body 400are illustrated as dashed lines 145 a in the top and bottom sections ofthe decanter cross section.

The weir 430 can be an interior wall or ring with an inner aperture 431.The weir serves as a wall to hold the cake and block it from exitingthrough the serum outlet 440. Thus, the weir separates the cake andserum portions and permits the less dense, thinner serum 140, to passthrough the decanter through the serum outlet 440. The weir height isselected such that the cake portion is retained against the innersurface of the centrifuge body, thereby separating the cake from theserum. The cake can be removed from the decanter via cake output 450near the bottom of the body. More specifically, the cake can be“scraped” off the inner surface of the rotating centrifuge bowls by, forexample, a rotating scraper or auger 460 (partially illustrated in FIG.4). The auger surfaces rotate along the inner surface of the centrifugebody, thereby removing the cake 145 a from the inner surface. The cakeis then directed to the cake outlet or discharge port 450. The scrapercan be configured to closely scrape the wall or be positioned furtheraway from the inner surface such that the scraper removes a smallerquantity of cake from the inner surface of the centrifuge body. Cake andserum separation can be adjusted by adjusting the rotation speed of thedecanter, rotating speed of the internal cake scraping auger (scrollspeed differential), product temperature and the height of the weir.

One example decanter or centrifuge 135 that can be used is a Tetra PakInc., NX438 centrifuge operating at approximately 3400 revolutions perminute (rpm), having a 132 millimeter (mm) pond depth weir plate and ascroll speed differential of 20-40 rpm. The separation efficiency of thedecanter is improved as the temperature increases. A temperature ofapproximately 180 to 190 degrees Fahrenheit typically results inseparation of the cake and serum portions at the example speed.

Those persons of ordinary skill in the art will recognize that otherscraping mechanisms can be utilized for removing cake from an innersurface of the centrifuge body. For example, instead of a rotatingauger, the scraper can be a member that is displaceable along one ormore of the inner top, bottom or side surfaces of the centrifuge body.Thus, the displaceable member can move from one end of the decanter tothe other end to remove cake from the interior decanter surfaces.

Having described the general system portions and decanterconfigurations, FIGS. 5A-B and 6A-B illustrate the method for processingtomatoes with the system. Referring to FIG. 5A, step 500, tomatoes arereceived and initially processed (e.g., cleaned, sorted, etc.). Forexample, a fruit dump with water flumes and a conveying elevator withwater or cleaning sprays can be used. The tomatoes are transported tothe chopping mechanism and, in step 505, are chopped into tomato pieces.Chopped tomatoes have a natural brix concentration of about 3-7 brix. Ofcourse, different tomatoes and different food products can havedifferent brix concentrations.

In step 510, enzymes are removed from or inactivated in the choppedtomato pieces. This process is referred to as “enzyme inactivation” or“enzyme breaking” or “hot breaking”. More specifically, enzymes that areinvolved in the reduction of viscosity can be removed from orinactivated in tomato pieces, e.g., pectin galacturonase, pectin methylesterase and other enzymes present in tomatoes that cause viscosityreduction.

Enzyme breaking can occur at “cold” or “hot” temperatures. In coldenzyme breaking, chopped tomatoes are subjected to approximately 150 to170 degrees Fahrenheit for a period of about 1 to 10 minutes. In hotenzyme breaking, chopped tomatoes are subjected to approximately 200 to230 degrees Fahrenheit for a period of about 15 seconds to 10 minutes.Whether hot or cold enzyme breaking is used can depend on the desiredviscosity effect. For example, tomato paste made from “hot broken”tomatoes typically has higher viscosity than “cold broken” tomatoes.However, tomato paste produced with hot broken tomatoes typically hasless vibrant color than tomato paste produced with cold broken tomatoes.Breaking parameters can be adjusted depending on operating parametersand the desired enzyme breaking effect.

Continuing with block 515, chopped and enzyme inactivated tomatoes areprocessed with a pulper or finisher, if necessary. The pulper/finisherremoves solids such as skins, seeds and/or other fibrous material fromthe tomatoes. The pulp and fibers remaining within the finished tomatoesor “juice” are reduced to a specific size. Pulping-finishing generallyoccurs at a temperature of approximately 190 to 210 degrees Fahrenheitif the tomato pieces are subjected to hot breaking. If the tomato piecesare subjected to cold breaking, the pulping-finishing process can occurat approximately 150 to 170 degrees Fahrenheit.

Pulping and finishing tomato pieces results in a tomato “juice” or pulpproduct (“tomato juice”). However, those persons of ordinary skill inthe art will recognize that “juice” can be formed by techniques besidespulping and finishing, e.g., by repeated chopping, crushing, or otheractions to form juice. Thus, the tomato juice is not necessarily aproduct of a pulping/finishing step.

The tomato juice can be initially concentrated, if necessary, byremoving water with an evaporator in step 520. The degree of evaporationcan depend on the initial liquid content of the tomato juice. Forexample, hot tomato juice or juice processed with hot breaking can beexposed to a vacuum (e.g., 10-30° Hg) to remove a percentage of waterfrom the juice. Thus, the more water that is removed from the juice, themore viscous or resistant to flow the juice becomes.

Continuing with step 525, tomato juice is separated or fractionated intoserum and cake portions with a decanter. One example decanterconfiguration for separating the portions is a weir and scraper or augerconfiguration. The cake portion is more viscous and contains higherpercentages of insoluble solids and pectins of the tomato. The cakeportion can comprise about 5% to 35% of the total tomato juice stream.Further, the cake portion typically includes a large percentage ormajority of lycopene and other “color” compounds. The cake portionincludes about 5%-60% insoluble solids by weight and about 3-16% solublesolids by weight. The cake portion can have a concentration of about 3to 13 brix.

The serum portion of the tomato juice stream is less viscous than thecake that includes lower percentages of insoluble solids and pectin ofthe tomato compared to the cake portion. The serum portion can compriseapproximately 65% to 95% of the total tomato juice stream by weight. Theserum portion includes about 0 (trace) amount to about 10% insolublesolids by weight and about 3%-17% soluble solids by weight. Further, theserum portion can have a concentration of about 3-16 brix.

In step 530, the serum portion 435 is concentrated. More specifically,the thin, less viscous serum fraction can be concentrated by removingwater with, for example, a smaller, less robust (and less expensive)evaporator compared to evaporators used in known systems which processunfractionated tomato juice. Examples of evaporators that can be used toconcentrate the serum portion in step 445 include, but are not limitedto, a rising film evaporator, a falling film evaporator, a thin filmevaporator, and other concentrating units such as a reverse osmosisconcentrator or a direct osmosis concentrator. The serum portion can beevaporated more easily than unfractionated juice because the thinnerserum can be re-circulated in the evaporator more often and more easily,resulting in improved heat transfer. Additionally, maintenance andcleaning and related costs can be reduced. As a result of lower levelsof insoluble portions in the concentrated juice, less or no cake isburned onto evaporator surfaces. Utilizing smaller and less robustevaporators is also beneficial because of lower capital and operatingcosts. Smaller evaporators can also operate under reduced heat ortemperatures, vacuum requirements, re-circulation requirements, andresidence time to evaporate a given amount of water from the serum.

If necessary, in step 535, the cake portion can be concentrated. Thethicker, more viscous cake portion contains higher percentages ofinsoluble solids and is also subjected to reduced heat, vacuum,re-circulation shear, and residence time. For example, instead ofprocessing the thicker cake portion in the unfractionated stream with anevaporator, the cake can be concentrated using a drying mechanism suchas a model no. 1 or a model no. 5 drier available from MCD Technologies,Inc., Tacoma, Wash. As a result, less cake “burn” occurs since ahigher-powered evaporator is no longer necessary to concentrate thejuice stream.

The fractionated cake and concentrated serum portions are re-combined instep 540 with a combination unit, e.g., a positive displacement pump oran in-line static mixer as previously described. Re-combining the cakeand serum portions results in the formation of a “re-combined” or“second” tomato stream 545. The brix concentration of the second stream545 is about 15 to 40 brix. During re-combination, all or a portion ofthe cake portion can be added to the concentrated serum. For example,50%-100% of the cake can be re-combined with the concentrated serum.Indeed, other cake percentages can be used depending on particular needsand desired viscosity (viscosity increases as percentage of cakeincreases). Increasing cake quantities lowers the brix of there-combined stream since the cake brix is approximately 3 to 20 brix,preferably 3-13 brix, while the serum brix is about 22-70 brix. As aresult, the concentration of the re-combined stream 545 can be about 15to 40 brix, preferably about 22-40 brix.

Continuing with FIG. 5B, the second or re-combined stream 545 can befurther concentrated in step 550, if necessary, and sterilized asnecessary in step 555. The re-combined stream is cooled if necessary instep 560. For example, the stream can be transferred to a flash cooler.Alternatively, a heat exchanger or other process may be used to cool thepaste. Those persons of ordinary skill in the art will recognize thatdifferent cooling systems can be utilized. The combined stream can bepackaged in step 565 or storage, shipping, sale, or consumption. As aresult, the resulting tomato paste product produced with the re-combinedstream has improved color, flavor and viscosity compared to tomato pasteformed by processing unfractionated tomatoes.

FIGS. 6A-B illustrate an alternative to the method shown in FIGS. 5A-B.In FIGS. 6A-B, the initial steps performed in the alternative method arethe same as the previously describe method. Namely, in steps 500-520,tomatoes are chopped, subjected to enzyme removal or breaking, processedusing a pulper/finisher, and subjected to preliminary evaporation, asnecessary. The tomato stream is fractionated 525 into serum and cakeportions as previously described. The serum portion is concentrated instep 530, and the cake portion can be concentrated as necessary in step535.

Instead of re-combining the cake and serum streams as in the method ofFIGS. 5A-B, the serum and cake portions in the alternative embodimentare individually processed. Specifically, in step 600, the serum portioncan be further concentrated if necessary. In steps 605, the serum andcake portions are sterilized as necessary. The sterilization step may beoptional if the concentration is sufficiently high to limitmicrobiological activity. In this alternative case, refrigerated storagemaybe used. In step 610, the serum and cake portions are cooled.Finally, in step 615, the serum and cake portions can be individuallypackaged or further processed. The fractionated cake and serum portionsare packaged for subsequent storage, shipping, sale, or consumption. Forexample, the tomato portions are transferred to bulk bag in bins,storage tanks or other storage containers. The final serum product canhave a concentration of about 22-75 brix. The final cake product canhave a concentration of about 3-13 brix or can be dehydrated into apowder with less than 10% moisture.

The previously described method and system result in a tomato paste withenhanced attributes compared to tomato paste and tomato productsproduced by known systems. For example, tomato paste produced with thepresent system and method has improved color, flavor, and viscosity.Moreover, the improved tomato paste product is produced in a more costefficient manner since smaller and less expensive and moreenergy-efficient evaporators can be used to fractionate the tomato juiceinto a more viscous and less viscous portions. As a result, reduced“burn on” occurs in the evaporator. The evaporator can concentrate thethinner serum, whereas a drying mechanism can evaporate or concentratethe cake as necessary, thereby reducing cake burn which would otherwiseoccur when processing unfractionated streams. Moreover, since the serumis significantly thinner than an unfractionated stream, the serum can beconcentrated with the evaporator more quickly than the time required toconcentrate an unfractionated stream. As a result, residence time of theproducts in the evaporator decreases and operating costs are reduced.Thus, the present system and method provide flexibility in selectingsystem portions, is more cost and time efficient, and produces higherquality tomato paste, serum, cake and other products similar or relatedto tomatoes.

Although references have been made in the foregoing description tovarious embodiments, persons of ordinary skill in the art of foodpreparation methods and systems will recognize that insubstantialmodifications, alterations, and substitutions can be made to thedescribed embodiments without departing from the invention as claimed inthe accompanying claims. Thus, while the preferred embodiment isdescribed as utilizing tomatoes, those skilled in the art will recognizethat other similar tomato products and fruits and vegetables havingsimilar viscosity characteristics can be processed. Further, persons ofordinary skill in the art will recognize that the example ranges ofconcentrations, temperatures, durations, and vacuum are recited forpurposes of explanation. Indeed, other ranges can be utilized dependingon the system portions and desired product characteristics. Moreover,those persons of ordinary skill in the art will recognize that variousdecanters, evaporators, driers and re-combiners can be used to processfractionated or re-combined cake and serum streams.

1. A method for producing tomato paste using fractionationconcentration, comprising: separating a tomato stream into a serumportion and a cake portion using a decanter that includes an inner weir,the serum portion comprising about 65-95% of the tomato stream byweight; removing water from the serum portion to form a concentratedserum portion; and combining the cake portion and the concentrated serumportion to yield the tomato paste, the tomato paste having aconcentration of about 22-40 brix.
 2. The method of claim 1, separatingthe tomato stream further comprising separating a tomato juice streamformed from raw tomatoes.
 3. The method of claim 1, the serum portionhaving a concentration of about 3-16 brix.
 4. The method of claim 1, theconcentrated serum portion having a concentration of about 22-75 brix.5. The method of claim 1, the cake portion comprising about 5-35% of thetomato stream by weight.
 6. The method of claim 1, the cake portionhaving a concentration of about 3-13 brix.
 7. The method of claim 1, thecake portion having a concentration of about 3-13 brix, the serumportion having a concentration of about 3-16 brix, and the concentratedserum portion having a concentration of about 22-75 brix.
 8. The methodof claim 1, the serum portion having up to about 10% insoluble solids.9. The method of claim 1, the cake portion having about 5-60% insolublesolids.
 10. The method of claim 1, separating the tomato stream furthercomprising adjusting a height of the inner weir to adjust the amount ofthe cake portion retained against an inner surface of the decanter. 11.The method of claim 1, the tomato paste having about 36% of the cakeportion by weight.
 12. The method of claim 1, the tomato paste havingabout 64% of the concentrated serum portion by weight.
 13. The method ofclaim 1, the tomato paste having about 36% of the cake portion and about64% of the concentrated serum portion by weight.
 14. A method forproducing tomato paste using fractionation concentration, comprising:separating a tomato stream into cake and serum portions using a decanterthat includes an inner weir, the cake portion comprising about 5-35% ofthe tomato stream by weight; removing water from the serum portion toform a concentrated serum portion; and combining the cake portion andthe concentrated serum portion to yield the tomato paste, the tomatopaste having a concentration of about 22-40 brix.
 15. The method ofclaim 14, separating the tomato stream further comprising separating atomato juice stream formed from raw tomatoes.
 16. The method of claim14, the serum portion comprising about 65-95% of the tomato stream byweight.
 17. The method of claim 14, the serum portion having aconcentration of about 3-16 brix.
 18. The method of claim 14, theconcentrated serum portion having a concentration of about 22-75 brix.19. The method of claim 14, the cake portion having a concentration ofabout 3-13 brix.
 20. The method of claim 14, the cake portion having aconcentration of about 3-13 brix, the serum portion having aconcentration of about 3-16 brix, and the concentrated serum portionhaving a concentration of about 22-75 brix.
 21. The method of claim 14,the serum portion having up to about 10% insoluble solids.
 22. Themethod of claim 14, the cake portion having about 5-60% insolublesolids.
 23. The method of claim 14, separating the tomato stream furthercomprising adjusting a height of the inner weir to adjust the amount ofthe cake portion retained against an inner surface of the decanter. 24.The method of claim 14, the tomato paste having about 36% of the cakeportion by weight.
 25. The method of claim 14, the tomato paste havingabout 64% of the concentrated serum portion by weight.
 26. The method ofclaim 14, the tomato paste having about 36% of the cake portion andabout 64% of the concentrated serum portion by weight.
 27. A method forproducing tomato paste using fractionation concentration, comprising:separating a tomato stream into a serum portion and a cake portion usinga decanter that includes an inner weir, the serum portion comprisingabout 65-95% of the tomato stream by weight and the cake portioncomprising about 3-35% of the tomato stream, the cake portion having aconcentration of about 3-13 brix, and the serum portion having aconcentration of about 3-16 brix; removing water from the serum portionto form a concentrated serum portion, the concentrated serum portionhaving a concentration of about 22-75 brix; and combining the cakeportion and the concentrated serum portion to yield the tomato paste,the tomato paste having a concentration of about 22-40 brix and about36% of the cake portion and about 64% of the concentrated serum portionby weight.
 28. The method of claim 27, separating the tomato streamfurther comprising separating a tomato juice stream formed from rawtomatoes.
 29. The method of claim 27, the serum portion having up toabout 10% insoluble solids.
 30. The method of claim 27, the cake portionhaving about 5-60% insoluble solids.
 31. The method of claim 27,separating the tomato stream further comprising adjusting a height ofthe inner weir to adjust the amount of the cake portion retained againstan inner surface of the decanter.